Thin Film Production and Characterization Ba1-xSrxTiO3 (x = 0.9)

The development of the era of many changes that occurs in materials is often studied by scientists of science. Ferroelectric is one of the unique materials to be studied and researched. Commonly used ferroelectric thin film materials include Barium Strontium Titanate (BST), Barium Titanate (BaTiO3) and Strontium Titanate (SrTiO3). The BaSrTiO3 material in the last year is highly reviewed and developed, from the above-mentioned ferroelectric thin films Ba0.8Sr0.2TiO3 which acts as a dielectric to increase the capacitance value of the capacitor [1]. This study is a study for the manufacture of BST thin film from a mixture of Barium Carbonate, Strontium Carbonate and Titanium Isopropoxide with a composition ratio of Ba and Sr 0.1: 0.9 or can be written Ba0,1Sr0,9TiO3. The treatment is made by sol gel method or with CSD model, then continuous spin coating and annealing process at temperature 600 °C, 650 °C and 700 °C. Light sensor made of thin film material Ba0,5Sr0,5TiO3 above Si substrate (100) p-type by means of chemical-assisted chemical solution deposition (CSD) method [2].The capacitor is one of the electronic devices that play an important role in the electronics circuit. The value of the capacitor depends on how much charge can be stored. This dependence leads to a capacity already limited to the capacitor. The capacitance of a capacitor can be increased by a dielectric material in the capacitor [3]. BST is a perovskite material based on Barium Titanate (BaTiO3) [4]. Figure 1 shows the perovskite crystal structure of the BST ferroelectric material [5]. Figure 1: The perovskite structure of ferroelectric material [5].


Introduction
The development of the era of many changes that occurs in materials is often studied by scientists of science. Ferroelectric is one of the unique materials to be studied and researched. Commonly used ferroelectric thin film materials include Barium Strontium Titanate (BST), Barium Titanate (BaTiO 3 ) and Strontium Titanate (SrTiO 3 ). The BaSrTiO 3 material in the last year is highly reviewed and developed, from the above-mentioned ferroelectric thin films Ba 0.8 Sr 0.2 TiO 3 which acts as a dielectric to increase the capacitance value of the capacitor [1]. This study is a study for the manufacture of BST thin film from a mixture of Barium Carbonate, Strontium Carbonate and Titanium Isopropoxide with a composition ratio of Ba and Sr 0.1: 0.9 or can be written Ba 0,1 Sr 0,9 TiO 3 . The treatment is made by sol gel method or with CSD model, then continuous spin coating and annealing process at temperature 600 °C, 650 °C and 700 °C. Light sensor made of thin film material Ba 0,5 Sr 0,5 TiO 3 above Si substrate (100) p-type by means of chemical-assisted chemical solution deposition (CSD) method [2].The capacitor is one of the electronic devices that play an important role in the electronics circuit. The value of the capacitor depends on how much charge can be stored. This dependence leads to a capacity already limited to the capacitor. The capacitance of a capacitor can be increased by a dielectric material in the capacitor [3]. BST is a perovskite material based on Barium Titanate (BaTiO 3 ) [4]. Figure 1 shows the perovskite crystal structure of the BST ferroelectric material [5]. The nature of the perovskite structure of the BST is due to a form with a concomitant with 3,951Å. This situation coincides with the BaTiO 3 crystalline structure (a = 3.991Å and c = 4.0108Å) and SrTiO 3 (a = 3.897Å) with Ba tau Sr being at zero. The Ti ion is at the center and the three oxygen atoms are at the center of the face. This structure will cause the Ba 2 + ions in BaTiO 3 to be replaced by Sr 2 + ions. Ti 4+ ions and O 2+ ions in BaTiO 3 will exchange places at the c-pipe where the Ba 2+ ion is in an almost symmetrical position. Sr 2+ ions, Ti 4+ and O 2+ ions in SrTiO 3 remain unchanged in the structure SrTiO 3 estimates [6]. CSD or sol gel techniques are one of the simplest and easiest ways of making nanoparticles. The usefulness of this method allows us to design the desired material at low temperatures and as an alternative to conventional methods [7].
These thin films will be characterized using X-ray Diffraction, FESEM and Impedance Spectroscopy, where the characterization using FESEM to obtain the thickness of the sample and characterization using impedance spectroscopy to obtain the value of the dielectric constant can be calculated using the equation: The dielectric constant ɛ' is a measure of the ability of a material to store a relative charge in a vacuum chamber [8]. The value of complex capacitance (C*) at a given frequency is obtained through the relationship:

Research Methodology
This research is done by using some step experimental method. The sample was prepared using a sol-gel method placed on a glass substrate using a spin coater and annealing at temperatures of 600 °C, 650 °C and 700 °C while for BST capacitor characterization using XRD, FESEM and Impedance Spectroscopy. Figure 2 shows the flow diagram of the research conducted in the manufacture of BST capacitors. The structure of thin film of BST is shown in Figure 3.

Results and Discussion
XRD characterization results can be seen in Figure 4 (a) shows the absence of the resulting diffraction peak against the 2θ angle. Without the temperature treatment the annealing structures can be amorphous. The sample has no crystal field but is amorphous [9]. The orientations (010) and (110) contained in the thin film PbZr 0,625 Ti 0,375 O 3 (PZT) were lost by treatment without annealing [10]. Figure 4b shows the resulting diffraction peak at a 2θ angle. Samples subjected to annealing temperature treatments have a crystal structure. Annealing temperature increases cause the atomic radius to increase in size so that the density becomes increased [11]. The intensity is proportional to the annealing temperature [12].    Table 1. Characterization using FESEM can be seen in the following Figure 6(a-c).    FESEM characterization of annealed samples at temperatures of 600 C, 650 °C and 700 °C produces thicknesses of Ba 0.1 Sr 0.9 TiO 3 capacitors. Figure 6(a-c) samples of BST annealing at temperatures of 600, m; 53.59nm and 87.09nm. Enhancement temperature an-nealing causes the size of BST layer thickness to be greater [14]. Annealing temperature increases cause the size of the BST constituent particles to be larger so that the atoms in it are more orderly and solid [15]. Characterization using Impedance Spectroscopy in order to know the value of complex capacitance, dielectric constant and dielectric loss. Values obtained at temperatures of 600 °C, 650 °C and 700 °C are shown in Figures 7-9 which are bode plot graphs ie the relationship between complex capacitance, dielectric constant and dielectric loss to frequency. Figures 7-9 are graphs of complex capacitance bode plot, dielectric constant and dielectric loss to frequency. Temperature 600 °C, 650 °C and 700 °C at 100Hz frequency of complex capacitance of 5.59x10 -11 F, 15x10 -11 F and 25 x10 -11 F.
The dielectric constant value is 6.32, 14.73 and 23.59. Dielectric loss value is 0.045; 0.11 and 016. The same frequency of complex capacitance values increases as a result of annealing temperature increases [16]. The dielectric constant increases with increasing annealing temperature from 550 °C to 800 °C [17]. The frequency rises from 100 Hz to 1MHz, dielectric decreases and dielectric losses increase sharply [18].

Conclusion
The XRD characterization shows intensity value increases with increasing annealing temperature and the resulting structure is cubic. FESEM characterization produces thickness. The thickness is directly proportional to the temperature. The characterization of impedance spectroscopy results in the value of complex capacitance, the dielectric constant inversely proportional to the frequency. Dielectric loss is directly proportional to frequency.